Friday, July 2, 2010

What makes a green building project?

The title of this entry was going to be "What makes THIS a green building project"?, but before I can answer that, there is a lot of ground to cover.

I feel like there is a lot of confusion surrounding green building and sustainability in general. This is partially because these have become buzz words and marketing tools in our society (see: Greenwash) and the true definition is easily lost or forgotten. 

Some greenwashing is less obvious than others. I bought some Fresh Aire Choice primer for our floors because it has no VOC's. It still smelled horrible like most paint. When I looked closer, I realized that it still carried the Prop 65 cancer warning label because it is still full of horrible toxins. 

The best place to start is the dictionary definition of the word "sustainable":

"...2 a : of, relating to, or being a method of harvesting or using a resource so that the resource is not depleted or permanently damaged..."

The simple conclusion is that this definition applies to the resources used to construct and the resources consumed by the building and it's occupants. I also think it's safe to say that when the term is used in building, it implies sustaining human life and livelihood as well as keeping our environment in tact. Using toxic building products is working against sustaining life in the small scale and short term as it is causing health problems for occupants. Irresponsible sourcing and manufacturing of resources is doing the same thing in the large scale and long term as it is destroying our eco system, threatening the very thing that sustains life on this planet. 

When taking all of this into consideration, you may begin to question the use of the word "sustainable". Are today's "green" construction practices really sustainable in every sense? In my opinion, they probably aren't in most cases, but I believe we are taking strides in the right direction.

With that out of the way, here is my approach to building green and working toward a sustainable future, broken down into three categories: Material Selection, Resource Efficiency, and Education & Behavior. A more complex breakdown would include advanced design and construction methods, but for now, they are scattered throughout these categories. 

Material Selection

The materials we choose to build with play a major role. We can no longer grab something off a shelf without considering these factors:
  1. Where did it come from and how was it sourced? Was it mined in a way that destroys an eco system or gives laborers health problems?
  2. Did it take copious amounts of energy to produce and transport to you? This is known as "embodied energy" and is most commonly referred to when discussing hybrid cars. There are many arguments that the embodied energy of a hybrid will never be offset by the efficient consumption and lower emissions of the car while it's on the road.
  3. Is it healthy for the building's occupants? We all know that lead paint and asbestos are no good, but most people aren't informed that their new carpets may be off-gassing toxins or that they are breathing formaldehyde used in the glue in their cabinets.
  4. If it's an appliance or fixture, does it have an acceptable efficiency rating? (More on this below)
  5. How durable is it? What is it's lifespan and where will it end up when it's done serving it's purpose in your building? 

These granite countertops may be durable and recyclable, but consider the other factors. They take extremely high amounts of energy to mine, cut, and polish. They very well may have been mined in Africa and processed in China before being shipped over here.

I'll use #5 to segway into further consideration on this point that needs it's own attention; Recycling. This is how I break down recycling in green building in order of most to least desirable methods:
  • On-site reuse. You really can't ask for a better product than one that can be reused with little or no effort. In a remodel, everything you avoid tearing out is great. Other things may need more effort. I recall seeing a house where the old roof was milled down into flooring.
  • Off-site reuse. Architectural salvage is one of the greatest things available in the building industry. If a remodel or even a tear down is done properly, the unwanted items and materials can easily be sold or donated to a salvage center, reused on another of your projects, sold on Craigslist, etc.
  • Traditional recycling. Think of the glass bottles you leave in the curb for pickup. In most countries, these are refilled and reused. In the good old US of A, we take the often unnecessary extra step of grinding them down, melting them, and forming new glass or using the grounds for reflective paint. Consequently, the materials obtain more embodied energy through transportation and processing. This method isn't as ideal as simple reuse, but it is sometimes the only option and it makes for some very cool building products. 

These floors will look brand new again with very little effort compared to replacing them. 

There is a concept called "Cradle to Cradle" that everyone should be aware of. This is the idea that at the end of it's useful life, a material will have a new purpose rather than ending up in a landfill. This is one of the most difficult goals to achieve because it means thinking, and caring, about what will happen to this material way in the future. 

EcoRock earned Cradle to Cradle Gold Certification by MBDC

Consensus: Materials need to be as healthy as possible for the environment, humans, and animals from the time they are sourced, through production and transportation, through their useful life, and into their next purpose. Where applicable, they need to be resource efficient. 

Resource Efficiency

Having discussed the effect that material selection has on resources, the next consideration is the efficient use of consumable resources. While this could entail a large number of things, the main resources break down into are water and energy. Although I believe water to be an equal issue, the focus in our country right now is energy. This can be looked at in a variety of different ways, but I like to break it down into three steps:
  1. The first and most important step is to use passive design to reduce the energy load or demand. Passive design typically refers to elements that are fixed and require no human or technological intervention, thus leaving no room for error. Sizing roof overhangs to shade the house in the summer and allow the sun to heat it in the winter is a great example. Proper insulation and air sealing is another.
  2. The next step then would be active design. The most common example would be the use of solar panels to convert the sun's rays into electricity or to heat water. (The probably with renewable energy systems is that they can be cost prohibitive - a good place to start would be switching to renewable energy through your utility company if they offer it) Another good example of active desgin is a heat recovery ventilator. This is a unit that uses a heat exchanger to recover as much heat as it can from stale air as it leaves the house and uses it to pre-heat fresh air before entering your furnace.
  3. The final step is to choose efficient fixtures, appliances, and systems. This is very easy and effective if the first two steps are properly followed. There is a wealth of knowledge online and most items are labeled with some sort of efficiency guide comparing them to other units on the market. 

This passive solar design will work without any human or computer messing with it. 

Now on to water. Most people don't see this as being a big issue, but it really is. We are depleting our reservoirs and underground aquifers (check this site out for more info) and allowing stormwater runoff to pollute clean water supplies (source: EPA). Therefore, a sustainable building project should properly deal with the following:
  1. Potable water conservation. The first step in designing for conservation is to use highly efficient plumbing fixtures and appliances. In the last few years alone, toilets have come to use way less water per flush than they used to. A more commonly overlooked step is designing the hot water system to run the shortest possible distance from tank to fixture and properly insulate the pipes. We waste a lot of water waiting for it to get hot. There are some systems available now that run a loop back to the hot water tank and keep the water from coming through until it's properly heated.

  2. Exterior water conservation. Minimizing exterior water demand makes a big difference and can be done by Xeriscaping. Eliminating grass and other "thirsty" plants, while using as many native plants as possible, will drastically reduce, or even eliminate the need to water outdoors.

  3. Stormwater management. Every time it rains, the average property retains very little of the water. Most of it runs off the roof, concrete, etc and into the city storm drains. On it's way to the drains, it often picks up toxins and bacteria that pollute our clean water. The easiest solution is to disconnect gutters from the stormwater system and make sure roof runoff is staying on your property. An existing driveway is tricky to deal with, but there are plenty of solutions for new installations such as paver stones or pervious concrete. There are exceptions where it is unlawful to capture stormwater, some with good reason, some without. Check with your local building code or water bureau.

  4. Water collection and reuse. So your stormwater is all draining into your property now? Why not collect some of it in rain barrels or a big tank so you can water with it during the summer? I've even toured some homes that collect enough water for their landscaping as well as personal use, but the cost of setting up collection and filtration on that scale is still prohibitive in most cases. If local building codes allow for it, grey water is an excellent way to irrigate. Water can be collected from your shower, sinks, and washing machine for outdoor use. This requires very careful selection of soaps, cleaning agents, shampoos, etc. 
Consensus: Green building projects need to start with a passive design customized for local climate and projected building use. If the budget allows, on-site renewable energy and water harvesting systems should be used. In most cases, stormwater should be kept from running off-site. Once the lower demand for resources has been established, pick out highly efficient fixtures and appliances.

Education & Behavior

Here is where we, as a country, have continued to fail since the beginning. You can build the most eco-friendly, energy efficient building, and still end up with negative results due to human behavior. If a person is going to leave lights on all day, leave doors open in the winter, or wash their car every day, they need to be educated on the consequences. 

In the LEED for Homes reference guide, the smallest, yet one of the most important chapters deals with education. It's required of builders applying for LEED certification to write a user's manual for the house and to do an in-depth walkthrough with the buyer. Additional points are given if the builder chooses to use the project for public outreach and education. 

Keep it up, buddy!

Consensus: No amount of design, proper planning, technology, or advanced building methods will really make the difference. It's up to everyone to be educated and be and educator. The politics surrounding sustainability will probably always continue to interfere with mass public education and we really have to take matters into our own hands. 

1 comment:

  1. Josh- thanks for the turorial- you should write a book!